Cargo trailers are widely used to transport various materials. For example, tipper trailers, dump trailers, and walking floor trailers, among others, are widely used to transport particulate bulk material such as gravel, stone, grain, and road salt, as well as other material such as municipal garbage or construction or industrial waste.
In some applications, trailers are loaded from a top opening of the trailer using a loader or directly from a feed source such as an overhead chute. In such case, the trailer may be provided with one, two, or more top doors which may be closed to protect the loaded material from contamination or from being disturbed or blown about or out of the trailer during transport. Each top door is typically mounted to the container along an adjoining upper edge of a sidewall of the container by means of a number of hinges.
In some conventional top-loadable cargo trailers, the top doors and hinges are configured such that the doors are not rotatable completely through 270°, with the result that in a fully open position the doors project outwardly from the sides of the container causing a hazard to workers and equipment moving about the trailer.
In other conventional top-loadable cargo trailers, the hinges project past the sidewalls of the container when the top doors are fully closed. In jurisdictions where cargo trailer widths are regulated and limited, however, and where the limitation includes any hinges such that the hinges must also fall within a regulated maximum trailer width, any overhang of the hinges results in a container having a smaller width and therefore a lesser capacity, which is a disadvantage.
There is therefore a material value in a top loadable cargo trailer wherein the top doors in a fully open position do not project outwardly so as to cause a hazard, but at the same time wherein the width of the container is maximized to enable maximum container volume.